Medical solutions and/or components may be stored in separate containers, which are mixed together prior to use. However, such an approach may compromise the sterility of the system and/or the process and may be relatively labor-intensive, which may lead to inconsistencies and/or mistakes (e.g., dilution of the admixture, formulation mistakes).
Alternatively, flexible containers having multiple compartments separated by peelable or frangible seals may be used in many industries such as, for example, the medical industry to separately store different medical solutions and/or components due, at least in part, to their stability and/or compatibility. These different medical solutions and/or components are admixed before use.
In operation, the peelable seal may be broken by, for example, purposeful manipulation of the flexible container, to mix the separately stored different medical solutions and/or components together. Some known flexible containers are produced and/or fabricated using flexible films or sheets that are joined along their peripheral edges to form the container. To enable the container to have, for example, a first chamber and a second chamber, a peelable seal may be utilized to separate the different chambers. Some flexible containers having multiple compartments are described in U.S. Pat. No. 4,770,295, U.S. Pat. No. 5,176,634 and U.S. Pat. No. 5,577,369, each of which is incorporated herein by reference in their entireties.
Peelable seals are commonly produced by two different methods. One of the methods includes precisely heating adjacent contacting surfaces of single layer sheets to soften or slightly melt the single layer sheets to create cohesive bonds without fully fusing the single layer sheets. Alternately, adjacent layers of multilayer polymeric flexible sheets may be precisely heated to soften or slightly melt the multilayer polymeric flexible sheets to create cohesive bonds without fully fusing the adjacent layers. The other of the methods may include precisely heating adjacent contacting surfaces of multilayered sheets that includes layers having different melting characteristics to soften or slightly melt the inner contacting layers to create a cohesive bond without fusing the outer layers, because the outer layers have a relatively higher melting temperature. Peelable seals, as described above, typically break by separating the sheets adjacent the peelable seal (e.g., delaminating at the seal).
The methods described above to produce peelable seals unfortunately produce peelable seals that are inconsistent (e.g., too strong or too weak), because of difficulties surrounding maintaining precise control of the temperature used to create the sealing boundary, especially in larger scale manufacturing processes. As such, some of the peelable seals produced using the above described methods may be too strong to break open after a particular amount of force is applied or too weak not to break open during normal handling and/or accidental dropping.